Barclays' board was told it was "a disgrace to capitalism". The directors of insurance giant Aviva were accused of being "more concerned about their remuneration packages than growing our business". At Man Group, the hedge fund manager with a shrivelled share price, the highly paid chief executive was asked, witheringly: "Sir, does it really feel like a $7m year to you?"

Yes, the boss-kicking season – aka, the spring round of annual shareholders' meetings – has offered splendid sport. Private shareholders have lobbed memorable insults from the floor and, in a new twist, institutional investors have thrown their block votes around.

Pay reports have been rejected at four companies (Aviva, car dealer Pendragon, miner Central Rand Gold, and on Thursday oil explorer Cairn Energy) and 25%-plus rebellions have been common. There have been trophies – the departures of three unloved chief executives: Andrew Moss of Aviva, David Brennan of AstraZeneca, and Sly Bailey of Trinity Mirror.

"To me it's capitalism renewing itself," says Simon Walker, director-general of the Institute of Directors. "Those of us who believe in free markets ought to be shouting from the rooftops."

It's true that something has changed this year: companies have discovered that token gestures don't work like they used to. Aviva volunteered Moss to take a £46,000 cut in his salary, a laughably small reduction for a chief executive who had a pay-plus-perks package of £5m in a year when the share price continued to fall.

Sir Ian Gibson, chairman of Trinity Mirror, similarly offered a tweak to Bailey's package: a cut in her short-term incentives in exchange for a bigger long-term carrot. Shareholders concluded that they were being fobbed off. And rightly so: Bailey had earned £14m in a 10-year spell in which Trinity Mirror's share price collapsed by 90%. Maintaining her basic salary at £750,000 a year looked plain arrogant.

Time to celebrate a successful revolution, then? Not so fast. Scratch the surface and you'll see that radical reform to the way companies are managed and directors are paid still lies years away.

There are at least four qualifications that make this revolt, at best, a work in progress. First, not all boardrooms are capitulating. Gareth Davis, chairman of William Hill, responded to a 50/50 vote on the bookmaker's pay report by saying the £1.2m retention award for chief executive Ralph Topping was justified by unique circumstances. He blamed some of his shareholders for being led by a firm of US governance advisers.

We've also heard what might be called the "Marcus Agius non-apology". The chairman of Barclays, presented with a one-third vote against the bank's pay report, said sorry for not having done "a good enough job in articulating our case". Aviva, on the wrong end of 54% vote, tried that one too. "We, and I personally, recognise that we can and should have done more to engage with our shareholders," said Scott Wheway, head of the pay committee.

But communication is not the issue. One cause of resentment at Barclays was straightforward: bonuses totalling £2.1bn towered over shareholders' dividends of £700m. Agius says the bank is committed to "realigning" the split to suit the new era of low returns in banking but, on the speed of the adjustment, the position of Barclays' board still seems to be, "We're the best judges."

Second, remember that votes that have teeth today concern the appointment of directors, and here there is little menace. This year's tally? Number of directors re-elected: a couple of thousand, or thereabouts. Number of directors removed by popular vote: nil.

Moss, Brennan and Bailey – amazingly – secured 90%, 100% and 85% support respectively for their re-election. The manner of Moss's removal is instructive. Instead of voting against his reappointment, critics voted against Aviva's pay report – a vote that is currently merely advisory. The purpose, apparently, was to "send a message" to the board.

The hint was taken: Moss' resignation followed within days. But why such a dance round the houses? Because institutional investors plead that it is too risky to deprive a company of its chief executive, even one judged to have failed. Even company chairmen are baffled. "I don't get it," says one. "How can they vote for a director and then demand his resignation? It doesn't make sense."

Indeed it doesn't. But it's the way institutions have always behaved. With a few honourable exceptions, they are rebels with reservations. We have to see how they behave when the government gives them new powers in the form of a forward-looking, binding vote on pay.

Third, remember that we've been here before. The last great pay revolt was in the mid-90s, when privatised utilities offering poor service and hosepipe bans were the chief villains. Some of those reforms stuck. "Three-year rollers" – contracts that gave a departing director three years' salary, even in cases of failure – had disappeared by the turn of the century.

But they were replaced by something just as advantageous to executives. "The median total remuneration of FTSE100 CEOs has risen from an average of £1m to £4.2m for the period 1998-2010," began business secretary Vince Cable's consultation paper on executive pay last year.

The mechanisms are well known. Pay schemes became more complex, medium-term incentive schemes flowered alongside long-term schemes, and the annual cash bonus became akin to a salary supplement. Executives could usually rely on one card coming up trumps sooner or later. Fund managers waved it all through.

It's true that there has been progress in dismantling the complexity: greater simplification, at least in company reporting, is happening. But will executives simply find new ways to load the dice? That's what happened last time.

Fourth, recall the shift in the makeup of shareholders. The National Association of Pension Funds – not a firebreathing body anyway, according to its critics – calculates that its members own about 11% of the UK stock market, down from almost 30% 20 years ago.

Fragmentation of ownership, and the arrival of more foreign investors, is a problem. Simply put, fund managers in charge of pools of money in Abu Dhabi, Hong Kong or Singapore are less inclined to think about boardroom governance in the UK than their counterparts in London or Edinburgh.

What's to be done? Lord Myners, a former Treasury minister, thinks the best solution lies in forcing shareholders to take responsibility for choosing directors. "What's happening now is a seasonal phenomenon, probably accentuated by a concern to show Vince Cable that things are changing," he says. "But these votes don't address the central issue that there is insufficient communication between the institutional investors and the independent directors and that will not be fixed until we have institutional investors being members of nomination committees that review the list of director candidates and take that sole preserve away from the chairman."

He is describing the Scandinavian model, and its introduction in the UK would mark a definite shift in the relationship between boards and shareholders. Cable's other review - into short-termism - may have something to say. But it's hard to detect a grassroots demand from pension fund trustees and fund managers to place representatives on nominations committees. "Interesting and may warrant further exploration" is as far as the NAPF goes.

For all the excitement this spring, one suspects next's year show will be a stale repeat. The audience is booing but the cast of non-executive directors who set pay remains the same.